Boosting High Contrast Imaging Capabilities of SPHERE
SPHERE+ is a project of upgrading the instrument SPHERE installed at the Very Large Telescope in Chile (ESO) since 2015. SPHERE has produced a significant amount of scientific results on exoplanetary systems: detection of exoplanets, characterization of their atmospheres, morphology and physical dust properties of circumstellar disks, but also in other science areas (active galactic nuclei, environment of evolved stars, small bodies in the Solar System…).
The limitations of SPHERE are now well understood. At the same time, we know that giant planets are rare beyond 10 astronomical units (au), the bulk of this population being likely located within 3-10 au. SPHERE+ has the objective to explore this very regions in exoplanetary systems.
We aim to implement the first phase of the project on sky by 2026.
SPHERE+ drivers
With respect to SPHERE, SPHERE+ is designed to :
1/ achieve deeper contrasts at closer angular separations to access the bulk of the giant planet population, building on the synergy with radial velocity surveys and the Gaia mission.
2/ observe fainter and redder stars to improve the complementarity with sub-millimeter observations with ALMA in the context of planet-forming circumstellar disks.
3/ increase the spectral resolution to characterize further young giant planet atmospheres.
Technical Solutions
To achieve these scientific goals, the SPHERE+ consortium proposed to upgrade SPHERE with two sub-systems :
- SAXO+ : a second stage adaptive optics system, sensing the wavefront in the infrared, downstream the first stage but operating faster.
- MEDRES : a MEDium RESolution integral field spectrograph with a spectral resolution of at least ~1000 in a narrow field of view of ~0.6”.